The present invention relates to a lever switch used for various electronic components and also to a detecting device using the lever switch.
A lever switch used for various electronic components is employed for the purpose of detecting the presence of a recording medium such as a tape and disc or the operation of a mechanism. As a lever switch used for the purpose of such detection, a leaf switch having a combination of a movable contact and a stationary contact which are made up of elastic sheet metal is well known.
With respect to such conventional switch, the description will be given in the following with reference to FIG. 13 and FIG. 14.
FIG. 13 is a side sectional view of a conventional lever switch. In FIG. 13, the lever switch comprises a box-type case 1 and a lever 2. The case 1 comprises an opening formed in front and an opening 1A formed at the left side. The case 1 is made of insulating resin. In the middle of a lever 2 is formed an axle portion 2A, and the axle portion 2A is rotatably retained in the case 1. A driving portion 2B at one end of the lever 2 is located within the case 1, and an operating portion 2C at the other end of the lever is protruded diagonally up to the left from the opening 1A of the case 1.
Each of a movable contact 3 and a stationary contact 4 which are made up of elastic sheet metal is embedded in an inner right-hand wall 1B opposed to the opening 1A of the case 1. The left end of the movable contact 3 elastically comes in contact with the top of the driving portion 2B of the lever 2 to move the operating portion 2C diagonally up to the left. Further, there is provided a contact portion 4A slightly curved at the left end of the stationary contact 4 opposed to the middle portion of the movable contact 3.
The front of the case 1 storing the movable contact 3 and stationary contact 4 therein is provided with a cover (not shown).
In the above configuration, when the operating portion 2C of the lever 2 is moved downward with a predetermined force, the driving portion 2B will rotate upward on the axle 2A, as shown in the side sectional view of FIG. 14. Accordingly, the left end portion of the movable contact 3 bends upward as it is pushed by the top of the driving portion 2B, and then the movable contact 3 will come into contact with the stationary contact portion 4A of the stationary contact 4.
When the operating portion 2C of the lever 2 is rotated only for a predetermined stroke, the left end portion of the movable contact 3 further moves upward. The middle portion of the movable contact 3 then pushes the contact portion 4A, and due to the pressure, the stationary contact 4 also bends upward. In this way, the movable contact 3 and stationary contact 4 come in contact with each other under a stable pressure.
When the operating force applied to the operating portion 2C of the lever 2 is released, the driving portion 2B will be pressed downward due to the elasticity of the movable contact 3 and stationary contact 4, thereby causing the lever 2 to be rotated and the operating portion 2C to be shifted back to the status of FIG. 13.
However, in a conventional lever switch as described above, the movable contact 3 is moved in the direction of switch height by the lever 2, making the movable contact 3 to come in contact with and apart from the stationary contact 4, and therefore, the switch is required to have a predetermined height equivalent to the movement of the movable contact 3. This makes it difficult to miniaturize the entire switch. Further, since a stable contact pressure is obtained between the stationary contact 4 and movable contact 3 when the stationary contact 4 also bends after movement of the lever 2 only for a predetermined stroke, these contacts are not in stable contact with each other when the lever 2 is halfway in operation.
A lever switch of the present invention comprises
(a) a case having an opening;
(b) a stationary contact disposed in the case;
(c) a common contact disposed in the case;
(d) a movable contact disposed in the case; and
(e) a lever having an operating portion and a driving portion,
wherein the movable contact is made of elastic metal,
the movable contact includes a stationary portion, a contact portion, and a curved portion located between the stationary portion and the contact portion,
the stationary portion is connected to the common contact, and
the movable contact is disposed in a state of bending so that the contact portion is able to be in contact or non-contact with the stationary contact.
Wherein the operating portion is protruded from the opening,
the driving portion is located inside the case and is abutting on the curved portion of the movable contact, and
when the operating portion is manipulated, the driving portion pushes the curved portion, and then the contact portion comes into contact with or apart from the stationary contact.
A detecting device of the present invention comprises
a casing;
a lever switch disposed in the casing;
a detection circuit electrically connected to the lever switch; and
a moving body inserted and detachably installed in the casing.
The lever switch has the same configuration as described above. When the moving body is inserted into the casing, the moving body acts upon the operating portion of the lever.
With the above configuration, it is possible to obtain a miniature lever switch reduced in thickness and size. Further, a lever switch assuring electrically stable contact can be obtained. Thus, the effects of such miniaturization and stabilization can be obtained at the same time. Moreover, it is possible to realize the miniaturization and stabilization of a detecting device by using such lever switch. Also, the detecting device is able to reliably detect the operation of the moving body.